Achalasia is the inability of the esophagus to deliver food to the stomach.
An otorhinolaryngologist is a doctor who specializes in the management and treatment of diseases of the ear, nose, throat and related structures of the head and neck.
The gastroenterologist is a doctor specializing in diseases of the digestive system including esophagus, stomach, intestines, colon and rectum, pancreas, gallbladder, bile ducts and liver.
Remember that for the proper selection of health professional that treats achalasia you must consider the nature, severity and symptoms you are presenting.